| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.29 |
| Score | 0% | 66% |
What is the area of a circle with a diameter of 4?
| 36π | |
| 4π | |
| 16π | |
| 81π |
The formula for area is πr2. Radius is circle \( \frac{diameter}{2} \):
r = \( \frac{d}{2} \)
r = \( \frac{4}{2} \)
r = 2
a = πr2
a = π(22)
a = 4π
The endpoints of this line segment are at (-2, 6) and (2, -2). What is the slope-intercept equation for this line?
| y = -x - 3 | |
| y = -x + 0 | |
| y = -2x + 3 | |
| y = -2x + 2 |
The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is 2. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, 6) and (2, -2) so the slope becomes:
m = \( \frac{\Delta y}{\Delta x} \) = \( \frac{(-2.0) - (6.0)}{(2) - (-2)} \) = \( \frac{-8}{4} \)Plugging these values into the slope-intercept equation:
y = -2x + 2
Solve for y:
-8y + 9 < -9 + 7y
| y < -4 | |
| y < 1\(\frac{1}{5}\) | |
| y < -\(\frac{7}{9}\) | |
| y < 1\(\frac{1}{8}\) |
To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the < sign and the answer on the other.
-8y + 9 < -9 + 7y
-8y < -9 + 7y - 9
-8y - 7y < -9 - 9
-15y < -18
y < \( \frac{-18}{-15} \)
y < 1\(\frac{1}{5}\)
A coordinate grid is composed of which of the following?
origin |
|
x-axis |
|
all of these |
|
y-axis |
The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.
If angle a = 28° and angle b = 24° what is the length of angle c?
| 128° | |
| 50° | |
| 118° | |
| 66° |
The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 28° - 24° = 128°